Rotary valve



R. CHILTON ROTARY VALVE March 14, 1939.

Filed Dec. 30, 1937 4 Sheets-Sheet l 7 INVENTOR RoLflA/p (Harm ATTORNEYMarch 14, 1939. RLCHILTON 2,150,541

ROTARY VALVE a v Filed Dec. 50, 1937 4 Sheets-Sheet 2 March 14, 1939.

R. CHILTON ROTARY VALVE 4 Sheets-Sheet 3 I Filed Dec. 30, 1937 INVENTOR202mm (711mm! 2% ATTORNE R. CHILTON ROTARY VALVE I Mafch 14, 1939.

Filed Dec. 30, 1937 4 Sheets-Sheet 4 INVENTOR ROLAND CHILTON PatentedMar. 14, 1939 UNITED STATES PATENT OFFICE mesne assignments,

to Wright Aeronautical Corporation, Paterson, N. J., a corporation ofNew York Application December 30, 1937, Serial No. 182,456

10 Claims.

This invention relates to rotary valves, particularly for internalcombustion engines and in certain respects, comprises improvements on mycopending application, Serial No. 119,727. The

objects and advantages of the invention will be obvious from, or will bepointed out, in the following description with reference to the drawingsin which:

Fig. 1 is an axial section on the line |--l of Fig. 4 through the top ofa cylinder incorporating the invention;

Fig. 2 is, an axial section on the line 2--2 of Fig. 4;

Fig. 3 is a transverse section (on reduced scale) on the line 3-3 ofFig. 2;

Fig. 4 is a plan view;

Fig. 5 is a section through ports on the line 55 of Fig. 4, and

Figs. 6, 7 and 8 are detail views of the valve and driving gear unit.

Referring first to Fig. 1, Ill designates a con- ,ventional piston,operating in a cylinder barrel I2 equipped with a cylindrical extensionor a combustion chamber 14 of reduced diameter provided with inlet andexhaust port openings Iii-18 in which are screwed connection sleeves2il22 for inlet and exhaust pipes indicated at 2426, Figs. 4 and 5.

Rotationally fitted in the cylindrical extension 14 is a split cuifvalve indicated in general by 28 and shown in detail, together with abevel gear 30, in Figs. 6, -7 and 8. The valve is equipped with anopening or port of width W, Figs. '7 and 3, suitably-related to thewidths and positions of the inlet and exhaust ports l6l8 to produce thedesired timing when the valve is rotated (at half speed in the case of afour-stroke engine).

It will be seen in Fig. 5 that the height of the valve is such that itoverlaps the top and bottom of the ports l6- -i8 and that the valve portopening W is cut through at the bottom of the valve,

but not at the top, where an element of width 32 (Fig. 7) extendsoverthe top of the yalve opening and in this element there is formed a slot34. The valve is made slightly oversize with respect to its cylinderseat I 4, and the slot 34 is arranged to be virtually closed when thevalve is sprung into position in the cylinder. The valve towards itsupper end is provided withan internal projecting annulus 36 in whichthere is formed a rectangular axial slot 31, the width of which isindicated at 38, Fig 8, and this slot is engaged by a key 40 integralwith a sleeve 42 which is, in turn, integral with the bevel gear 30.

The gear sleeve 42 at its bottom end is equipped with an in-turnedflange 44 engaging an annular face 46 formed on a cylinder head 48 tocomprise a seal under the axial pressure imposed on the 4 sleeve 42, dueto cylinder pressures. At its lower end, the gear sleeve 42 is alsoprovided with a slight external shoulder 50 which engages acorresponding shallow recess turned in the inside of the valve.Thevalve, being split, is capable of being sprung over the projection.50 so that the valve and gear are relatively located axially while theintegral key 40 forms the rotary driving connection therebetween.

Prior to this assembly, there is introduced between the upper end of thevalve 28 and the lower face of the bevel gear 30 a bearing ring or plate52, which ring is interposed between the upper end of the cylinderextension I and the head 48, the parts being clamped to form a gas tightjoint by bolts 54.

It will now be seen that ring 52 comprises a thrust bearing, locatingthe bevel gear 30 from downward displacement, and the valve 28 fromupward displacement and that this ring 52 is further provided withintegral cooling fins 56, substantially co-extensive radially, withcooling fins 58 formed on the cylinder itself in the usual way, and fins59 formed on the periphery of the head 48. The gear sleeve 42 is arunning fit in the bore of the bearing plate 52 which, accordingly,provides also for the radial location of the bevel gear 30 which has aradial clearance, shown exaggerated at 60, with respect to the head 48to allow for the expansion of the latter under running conditions. Itwill be seen that the integral fins 56 provide for direct cooling of thevalve and gear locating bearings of the ring 52 and certain objects andadvantages of the present invention reside in this structure.

Meshed with the bevel gear 30 is a small bevel pinion 62 having anintegral shank 64 engaged in a bushing 66 in a detachable liner 69clamped in position by a'bevel gear housing 10 which is secured to anextension 12 of the cylinder head by studs 14. The bevel pinion shank 84has a splined extension 16 and a further cylindrical extension 78 onwhich an outer bevel pinion 80 is free to float axially under theinfluence of the spring 82 by which the bevel gear 62 is urged to theleft to cause a spherical sealing washer 84 to make sealing contact witha spherical seated flange 86 on the bushing 66.

A vertical drive shaft 88 has a bevel gear 90 formed integral at itsupper end to mesh with the bevel gear 80, the shaft being supported in asuitable bushing 92 fitted in the housing iii. A

fitting 84 extends downwardly from the housin [8 forming the upper partof a suitable closure around the shaft 88, these parts extending down tothe crankcase of the engine (not shown). The

.combustion space is provided with a running seal between the head 48and the flange 44, at 46 is provided with a labyrinth seal, which maycarbon up without causing trouble between the sleeve 42, and the valve28 and by the bevel gear seal at 8486. The small clearances between thevalve and gear sleeve and between the gear sleeve and ring provide alabyrinth whereby the pressure in the chamber occupied by ithe gear andpinion teeth, sealed at 8 4-.-86, may become substantially the meanpressure between maximum and minimum pressures in the combustion. space,while the running seal at 46 prevents carbon entering intothe space 88between the head and sleeve 42, since these parts must have substantialclearance for expansion and contraction. Accordingly the annular groovein [the head 28 occupied by the gear 38 operates under a relativelyconstant low pressure, and is efiectively sealed from leakage by theseal 84-88.

The cylinder head has transverse fins 98 and is equipped with a pair ofspark plugs 88 and with an air jacketing cover I88 to which is secured asmall depending baflle I82, proportioned so that the air flow areabetween this bafile and the plugs through the depressed portion of thehead is proportional to the flow areas at the entering and exit portionsof the finning.

Referring now to the cross section of the valve 28 in Fig. 3, it will beseen that the working surface is covered with a facing I84, the valvesurface being recessed so as to leave lands I86 which prevent the edgesof the valve facing material from being exposed. This valve facingmaterial is composed of powdered material sintered onto the body of thevalve and subsequently finished therewith. The advantages of suchmaterial (on account of its porosity which enables it to retainlubricant) is known in the case of clutch plates where it has recentlygone into extended use with beneficial results, and the application ofthis material in this non-analogous environment to comprise a scompositevalve is included in the objects and advantages of this invention, incombination with the protection of the edges of the sintered materialwhich has given trouble with chipping in the case of clutches, and wouldbe particularly subject to erosion by the exhaust gases in thisembodiment.

A further advantage of this design resides in the simplified geometrydeveloped in the port disposition which permits highly efficient finningto be machined with the minimum of operations. Referring to Fig. 3, itwill be seen that by means of the screwed in sleeves 2822, the studbosses of the conventional flange and bolt connections are eliminatedwhereby all of the fins are opened to an un-interrupted airflow andwhereby further, the fins themselves may be produced by profiling withgangs of milling cutters. A further advantage of the specific designresides in the simplicity of the bailles needed to confine the airflowto the finned periphery, according to the requirements of currentpractice. These are indicated in dot and dash lines at I88, it beingunderstood that they will extend to the next adjacent cylinder of aradial engine.

The specific gearing by which the vertical drive shafts 88 are drivenfrom the engine crankshaft form no part of this invention, and,accordingly. need not be shown.

Reference is now made to the section of Fig. which illustrates animproved self aligning pipe connection used in conjunction with thescrewedin port sleeves 28-22 and here shown in conjunction with theexhaust port sleeve 22. -The sleeve 22 has an angular flange II8, theinner and outer surfaces of which are both formed radii having a commoncenter R. The exhaust pipe 28 has a bead H2, one surface of whichengages the inner spherical surface of the flange II8, the other side ofthe bead being angled in the opposite direction to cooperate with asplit clamp ring II i contacting the bead H2 and the flange I ID bywhich the parts are drawn together by means of screws II 6, Fig. 4. Thebead member H2 is preferably secured to the exhaust pipe 26 by welding.This structure provides a. quick detachable connection which ofiers aminimum of obstruction to the airflow into the fins, and comprises, in asense, a ball and socket connection, wherein the tube 28 may angulateslightly with respect to the sleeve 22 while still maintaining a tightlysealed'joint and full contact of the flange, bead and ring.

In the case of the inlet pipe, a conventional screwed gland and packingconnection II8 is used. Such connections have been found unsatisfactoryfor the h t exhaust pipes which are subject to rapid co osion, by whichsuch large threads are apt to become frozen" and cannot be disassembledwithout destroying the parts.

While I have described my invention in detail in its present preferredembodiment, it will be obvious to those skilled in the-art, afterunderstanding my invention, that various changes and modifications may.be made therein without departing from the spirit or scope thereof. Iaim in the appended claims to cover all such modifi tions and changes.

I claim as my invention:

1. In an engine cylinder, a cylindrical extension defining a combustionchamber, a cylinder head, cooling fins extending from said extension andhead, a bearing plate clamped between said cylinder and head and havingcooling fins extending therefrom and a rotary valve engaged in saidextension and bearing against said plate.

2. In combination, a rotary valve, a cylinder member within which saidvalve is seated, a cylinder head member, and a valve bearing memberinterposed between the first two said members, all three said membershaving cooling fins extending therefrom.

3. The combination with a cylinder and 9. cylinder head having'fins, ofa bearing plate interposed therebetween also having fins, and a valvemember rotationally engaging said cylinder and said plate.

4. A rotary valve for an engine cylinder comprising in combination, asleeve having a port opening formed therein and a slit between an end ofsaid sleeve and said opening whereby the sleeve is elasticallyexpansible, a driving gear insleeve engaging the inner circumference ofsaid valve, a key slot in said valve and a key integral with said sleeveand engaging said slot to drive the valve rotationally, and a projectionin the other over which the valve may be sprung for assembly in virtueof said elasticity.

6. In combination, a cylinder, a cylinder head having a projectiondefining an annulus within the upper portion of said cylinder, a gearhaving a sleeve'and a rotary valve engaging said sleeve in said annulusand means to seal said annulus comprising a flange on said sleeveengaging a seat formed on said head projection. l

7. The combination with a rotary valve of a gear having a sleeve engagedin said valve, a bearing plate interposed between said sleeve and valveto axially locate the same, a cylinder in which said valve isrotationally engaged, and a head closing said cylinder, said bearingplate being clamped between said head and cylinder.

8. A cylinder head having avcylindrical extension and an annular recess,a gear in said recess having a sleeve embracing said extension, a flangein-turned from said sleeve and a face formed on said extension withwhich said flange engages for the purpose oi sealing said annulus.

l9. A rotary valve for an internal combustion engine including a valvecylinder, a cufi valve within the cylinder, an annular plate atop thecylinder with which the top of the cut! valve is in running engagement,a cylinder head including an annular groove mounted atop said plate, abevel gear in said annular groove having a depending sleeve within anddrivably engaging said valve and forming therewith a labyrinth sealbetween the combustion space and said annular groove,- a bevelpinionjournalled in the head driving said gear, and a second sealbetween said bevel pinion and said head.

10. In a rotary valve for an internal combustion engine, a valvecylinder, 9. cufl valve therein,-

a cylinder head having an annular groove, driving means tor said valvewithin said groove, pri:

mary sealing means between said valve and cylinder head, means passingthrough said head in driving engagement with said driving means, andsecondary means sealing said annular groove with so I respect to themeans which passes through the cylinder head.

ROLAND CHILTON,

